Edinburgh Napier University

  The geotechnical behavior and settlement in landfills has been changing for many years. This behavior in fact depends on many factors and, therefore, making forecasts is complicated due to the effect of biodegradation. In order to solve this issue, most authors describe settlements as being the result of five mechanisms (load, mechanical creep, biodegradation, physical-chemical mechanisms, and interactions between them). Based on this information, authors propose three types of settlement (initial, primary, and secondary). This approach establishes a relationship between these mechanisms and the magnitude of the settlements, as well as time. Hence, it is widely believed that initial and primary settlement occurs during the first month. Then, secondary settlement such as mechanical creep, physical-chemical mechanisms, and biodegradation occurs. This can take more than 30 years. The current models for calculating settlements use different terminologies and terms, but they usually coincide as regards duration and time. In this work, different settlement models are analyzed in order to apply them as a new component of a calculation tool for landfills called LABWASTE.20. Furthermore, in this research, a total of fifteen mathematical models for settlement calculation have been analyzed (three of them simulate primary settlements and the other twelve simulate secondary settlements). Therefore, the advantage to be gained from this research for the environment consists in simplifying the calculation of settlements in landfills so as to be able to estimate the increase in volumetric capacity after settlement. LABWASTE.20 would then calculate the additional volumetric capacity achieved as a consequence of settlement in the waste mass